Energy and fuels are essential in modern life. Most widely used type of fuels are fossil fuels. Fossil fuels, e.g., natural gas, are essentially hydrocarbons containing carbon and hydrogen in various ratios. Natural gas, like any carbon-containing fuel, forms carbon dioxide upon its combustion, and therefore is not renewable on the human timescale. Also, because carbon dioxide is a greenhouse gas, combustion of natural gas contributes to global warming. It has been suggested to mitigate harmful carbon dioxide emissions by imposing carbon quota or by capturing carbon dioxide emissions and sequestering it underground or at the bottom of the sea. Sequestration, however, is a costly and only a temporary solution that presents a risk that sequestered carbon dioxide may be released with deadly catastrophic consequences in geological events such as earthquakes and slides. Thus, it would be desirable to make natural gas use environment-friendly, especially since natural gas is an abundant and major source of fossil fuel.
Also, it would be desirable to utilize carbon dioxide that frequently accompanies natural gas production. For example, natural gas wells in Algeria produce gas with up to 45% carbon dioxide content, and natural gas platforms in North Sea produce gas containing some 10-15% carbon dioxide. Carbon dioxide must be separated in natural gas production and is usually released into the atmosphere. Efforts also have been made to capture, separate and dispose of carbon dioxide by sequestering in subterranean cavities, depleted oil fields, or at the bottom of the sea. Sequestration, however, is only a temporary and potentially dangerous solution. Thus, an improved way of utilizing carbon dioxide that accompanies natural gas production is desired.